bug: Langfuse Open AI SDK on Node doesn't create all generations for a trace

[khaelys]

Describe the bug

I have a trace with 3 generations and I'm trying to use the new Langfuse SDK for OpenAI. The trace is created correctly, but not all generations get flushed to cloud langfuse, if I don't do it manually.

I expect that all generations get flushed to cloud langfuse under the hood without doing it manually.

To reproduce

How to reproduce.

• Create a trace
• Run 3 generations in parallel
• Await for all the 3 generations to complete and return
• Ensure the application is long-lived as per https://langfuse.com/docs/sdk/typescript/guide#lambda

const newTrace = this.langfuse.trace({
      name: 'myTrace',
      userId: userInfo.userId,
      sessionId: userInfo.sessionId,
      metadata: metadata,
      tags: [this.configService.get().appEnv],
});

// Example of my generation Method
async function myGenerationMethod(options): Promise<string> {
   const lfOpenAi = observeOpenAI(this.openAi, {
        parent: options?.trace,
        generationName: options?.prompt.name,
        langfusePrompt: options?.prompt,
        metadata: {
          env: this.configService.get().appEnv,
          ...options?.metadata,
        },
      });
      const chatCompletion: OpenAI.Chat.ChatCompletion =
        await lfOpenAi.chat.completions.create(params);
      this.checkFinishReason(chatCompletion.choices[0].finish_reason);
      return isNotNull(chatCompletion.choices[0].message.content);
}

await Promise.all([myGenerationMethod(), myGenerationMethod(), myGenerationMethod()]);

If you run a similar example multiple times, some generations are not recorded correctly.

SDK and container versions

I'm using "openai": "4.43.0" and "langfuse": "3.9.0" on Node 18

Additional information

No response

Are you interested to contribute a fix for this bug?

No